A structured framework and language for scenario-based life cycle assessment

It is common to have numerous alternatives and conditions that remain uncertain, but these need to be assessed in decision-making processes. Investigators introduce decision-makers' anticipations and assumptions into analysis when building strategies as a form of scenario. In such a way, scenario analysis is often used as a powerful vehicle for decision making. While a number of LCA case studies dealing with scenarios have been performed, structured frameworks integrating LCA with scenario analysis methodologies have not yet been established. In this paper, we first propose a general framework for scenario-based LCA. The framework provides retrospective and prospective studies with a clear structure. The most important characteristic of the structure is the recognition and separation of three modeling processes, lifecycle modeling, scenario modeling, and valuation modeling, to aim at an increase in reviewability of the entire study and reusability of the constructed models. Next, we introduce a tool, termed lifecycle modeling language (LCML), developed for modeling lifecycle systems and valuation procedures with its relevant scenarios within the proposed framework. LCML facilitates accumulating knowledge obtained from scenario-based LCA studies, by reusing the constructed models, or by applying the same patterns identified from the LCML description, and contributes to reducing the time and efforts needed for an investigation. An illustrative example is presented to show the functionality of LCML.